Method and apparatus for providing remote access service

ABSTRACT

A remote access service is provided by receiving remote access transport agent (RATA) capability information of a home remote access server (RAS) and a remote RAS from the home RAS and the remote RAS, respectively, generating a RATA profile based on the RATA capability information, supported by the home RAS and the remote RAS, and transmitting the generated RATA profile to the home RAS and the remote RAS, respectively.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.12/465,679, filed May 14, 2009, which claims the benefit under 35 U.S.C.§119 of a U.S. Provisional Application No. 61/071,872, filed May 22,2008 in the United States Patent and Trademark Office, and Korean PatentApplication No. 10-2008-0124291, filed Dec. 8, 2008 in the KoreanIntellectual Property Office, the disclosures all of which areincorporated herein in its entirety by reference.

BACKGROUND

1. Field

The following description relates to a universal plug and play (UPnP)middleware-based home network.

2. Description of the Related Art

Due to the spread of home networking, conventional home networkingenvironments centering on personal computers (PCs) are graduallyshifting to home networking environments including electronic equipmentsusing various lower networking technologies. As a result, home networkmiddleware technologies such as universal plug and play (UPnP) are beingdeveloped to group such electronic equipments in a unified network byusing Internet protocols (IPs).

UPnP technology enables home appliances in a home network to bepeer-to-peer networked on the basis of a distributed and open networkingstructure instead of being under centralized control.

Generally, in home network middleware, a UPnP device models its servicewith actions and state variables. A UPnP control point (CP)automatically discovers the UPnP device to use the service.

UPnP Device Architecture 1.0, for example, uses distributed and opennetworking to discover a UPnP device via an IP multicast in a homenetwork. It cannot currently be guaranteed that an IP multicast serviceis provided across the Internet, and thus controlling the UPnP deviceusing information obtained from the discovery of the UPnP device may bedifficult to perform across the Internet.

As a result, UPnP Remote Access Architecture has been developed suchthat a UPnP device or a CP is operated in a home network as if theyexist in the same network even if the UPnP device or the CP physicallyexists outside the home network. The UPnP Remote Access Architecturedefines a remote access server (RAS) existing within a home network anda remote access client (RAC) existing in a remote network.

SUMMARY

In one general aspect, a remote access service is provided by using amanagement console. The remote access transport agent (RATA) capabilityinformation of a home remote access server (RAS) and a remote RAS arereceived from the home RAS and the remote RAS, respectively, a RATAprofile based on the RATA capability information is generated, such RATAprofile being supported by the home RAS and the remote RAS, and thegenerated RATA profile is transmitted to the home RAS and the remoteRAS, respectively.

An identifier (ID) of the remote RAS may be transmitted to the home RAS,where the ID of the remote RAS is used for setting a secureauthenticated channel (SAC) established to the remote RAS by the homeRAS, and the RATA capability information may be received from the homeRAS by using a universal plug and play (UPnP) action, and the ID of theremote RAS and the RATA profile may be transmitted to the home RAS byusing the UPnP action, and the RATA capability information may bereceived from the remote RAS on the SAC by using an out-of-bandprotocol, and the RATA profile may be transmitted to the remote RAS onthe SAC by the out-of-band protocol.

The out-of-band protocol may include hypertext transfer protocol (HTTP)and secure-hypertext transfer protocol (S-HTTP).

RATA configuration information including the RATA profile of the remoteRAS may be obtained from the home RAS.

The RATA configuration information may be provided to the home RAS via aremote access discovery agent (RADA) Sync service of the remote RAS.

The RATA profile to be transmitted to the home RAS and the remote RAS,respectively, may be updated.

A RATA profile of each of the home RAS and the remote RAS may bereceived from the home RAS and the remote RAS, respectively, and amessage for deleting the received RATA profile may be transmitted to thehome RAS and the remote RAS, respectively.

If the management console moves to a remote network, the RATA capabilityinformation may be received from the home RAS through remote access byusing a UPnP action, and the RATA profile may be transmitted to the homeRAS through remote access by using the UPnP action, and the RATAcapability information may be received from the remote RAS by using theUPnP action after the remote RAS is discovered, and the RATA profile maybe transmitted to the remote RAS by using the UPnP action after theremote RAS is discovered.

If the management console is in a network address translation(NAT)-based private network, an address of a session initiation protocol(SIP) server in which a RAS of the private network subscribes transportaddress (TA) set information corresponding to candidate Internetprotocols (IP) addresses to traverse NAT may be transmitted to the RASof the private network.

If a relaying service to traverse NAT is provided to the RAS of theprivate network via a traversal using relays around NAT (TURN) server,an address of the TURN server, which is subscribed to by the RAS of theprivate network, may be transmitted to the RAS of the private network.

An SIP ID of the remote RAS may be transmitted to the home RAS.

The remote RAS may include a remote remote access client (RAC) or aremote remote access server (RAS).

In another general aspect, a remote access service is provided by usinga home remote access server (RAS). A session initiation protocol (SIP)identifier (ID) of a remote RAS is received from a management console, apayload of a SIP packet including a SIP ID of the remote RAS andtransport address (TA) set information corresponding to candidateInternet protocols (IP) addresses to access the home RAS is generated,and the SIP packet is transmitted to a SIP server.

The SIP packet including the TA set information corresponding to thecandidate IP addresses may be received to access the remote RAScorresponding to the SIP ID of the remote RAS as a payload of the SIPpacket, from the SIP server, a payload including TA set information ofthe remote RAS may be extracted from the SIP packet, and TA setinformation of the remote RAS may be set.

The TA set information of the home RAS may include a TA, a reflexive TA,and a relaying TA, and the TA may include a pair of an IP addressallocated to the home RAS and a port number of a service to access, thereflexive TA may include, when the home RAS is in a network addresstranslation (NAT)-based private network, a pair of a public IP addressallocated to the private network and a port number of a service toaccess. The relaying TA may include, when the home RAS is in a NAT-basedprivate network and packets destined for the private network are relayedby a traversal using relays around NAT (TURN) server, a pair of a publicIP address allocated to the TURN server and a port number of a serviceto access.

The TA set information of the remote RAS may include a TA, a reflexiveTA, and a relaying TA, and the TA may include a pair of an IP addressallocated to the remote RAS and a port number of a service to access.The reflexive TA may include, when the remote RAS is in a NAT-basedprivate network, a pair of a public IP address allocated to the privatenetwork and a port number of a service to access, and the relaying TAmay include, when the remote RAS is in a NAT-based private network andpackets destined for the private network are relayed by a TURN server, apair of a public IP address allocated to the TURN server and a portnumber of a service to access.

TA set information corresponding to the candidate IP addresses may begenerated to access the home RAS.

The payload of the SIP packet may be in a form of extensible markuplanguage (XML) or session description protocol (SDP).

The remote RAS may include a remote remote access client (RAC) or aremote RAS.

In another general aspect, a management console includes a remote accesstransport agent (RATA) capability information receiving unit receivingRATA capability information of a home remote access server (RAS) and aremote RAS from the home RAS and the remote RAS respectively, a RATAprofile generating unit generating a RATA profile based on the RATAcapability information, supported by the home RAS and the remote RAS,and a RATA profile transmitting unit transmitting the generated RATAprofile to the home RAS and the remote RAS, respectively.

In another aspect, a home remote access server (RAS), includes anidentifier (ID) receiving unit receiving a session initiation protocol(SIP) ID of a remote RAS from a management console, a SIP payloadgenerating unit generating a payload of a SIP packet including a SIP IDof the remote RAS and transport address (TA) set informationcorresponding to candidate Internet protocols (IP) addresses to accessthe home RAS, and a SIP packet transmitting unit transmitting the SIPpacket to a SIP server.

Other features and aspects will be apparent from the following detaileddescription, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an exemplary architectureproviding a home-to-home remote access service between a remote remoteaccess server (RAS) and a home RAS.

FIG. 2 is a block diagram illustrating an exemplary architectureproviding a home-to-home remote access service between a remote RAS anda home RAS by using a management console within a moving remote accessclient (RAC) that remotely accesses to the home RAS.

FIG. 3 is a diagram showing an exemplary process of transmitting aremote access transport agent (RATA) profile in order to provide ahome-to-home remote access service.

FIG. 4 is a diagram showing an exemplary process of updating a RATAprofile in order to provide a home-to-home remote access service.

FIG. 5 is a diagram showing an exemplary process of deleting a RATAprofile in order to provide a home-to-home remote access service.

FIG. 6 is a diagram showing an exemplary process of transmitting a RATAprofile by using a management console within a moving RAC that remotelyaccesses to the home RAS, in order to provide a home-to-home remoteaccess service.

FIG. 7 is a diagram showing an exemplary process of traversing networkaddress translation (NAT) by using a session initiation protocol (SIP).

FIG. 8 is a diagram showing an exemplary process of traversing NAT,provided by a traversal using relays around NAT (TURN) server, by usinga SIP.

FIG. 9 is a diagram showing an exemplary process of transmitting addressinformation for setting a secure authenticated channel (SAC) and avirtual private network (VPN), which traverse NAT, by using a SIP and aformat for describing a set of NAT traversing addresses using a sessiondescription protocol (SDP).

FIG. 10 is a block diagram illustrating the structure of an exemplarymanagement console.

FIG. 11 is a block diagram illustrating the structure of an exemplaryhome RAS.

Throughout the drawings and the detailed description, unless otherwisedescribed, the same drawing reference numerals will be understood torefer to the same elements, features, and structures. The relative sizeand depiction of these elements may be exaggerated for clarity,illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader ingaining a comprehensive understanding of the media, methods,apparatuses, and systems described herein. Accordingly, various changes,modifications, and equivalents of the media, methods, apparatuses, andsystems described herein will be suggested to those of ordinary skill inthe art. Also, descriptions of well-known functions and structures maybe omitted for increased clarity and conciseness.

FIG. 1 shows an exemplary architecture providing a home-to-home remoteaccess service between a remote remote access server (RAS) 130 and ahome RAS 150.

Referring to FIG. 1, the home RAS 150 is a universal plug and play(UPnP) device existing within a home network, and the remote RAS 130 isa UPnP device existing within a remote network. The home RAS 150 is alogical device supporting a remote access service, and may be either adevice physically identical to an internet gateway device (IGD) or adevice different from the IGD. A management console 190 is a device forsetting configuration information related to remote access andcontrolling the remote access service. In other words, the managementconsole 190 is a UPnP control point (CP) for controlling the remoteaccess service. The management console 190 according to an exemplaryembodiment may be included in the home RAS 150 or may be a deviceseparate from the home RAS 150. New UPnP actions and state variables maybe defined in, for example, the home RAS 150, the remote RAS 130, andthe management console 190.

The home RAS 150 and the remote RAS 130 synchronize device listinformation, discovered in networks of each of the home RAS 150 and theremote RAS 130, via a remote access transport channel (RATC)therebetween. Thus, the remote RAS 130 can discover UPnP devices withinthe home network. Then, the home RAS 150 forwards a message forcontrolling a device, received by the remote RAS 130 via the RATC, to aUPnP device corresponding to the message.

The management console 190 provides parameters, which are used forsetting the RATC between the home RAS 150 and the remote RAS 130, in theform of remote access transport agent (RATA) profiles. The managementconsole 190 matches information regarding protocols to be used by RATAs151 and 131 of the home RAS 150 and the remote RAS 130 and capabilityinformation, and generates a RATA profile for each of the home RAS 150and the remote RAS 130 based on the matched information.

The home RAS 150 and the remote RAS 130 set the RATA profile withinthemselves, so that the RATC can be set up between the home RAS 150 andthe remote RAS 130 later.

If the home RAS 150 and the remote RAS 130 exist in the same network,the management control 190 may set up the RATA profile dynamicallyaccording to, for example, UPnP Device Architecture 1.0. Nevertheless,the remote RAS 130 and the home RAS 150 supporting home-to-home remoteaccess need not exist in the same network or move to the remote network.

Thus, the management console 190 may generate and transmit the RATAprofile in order to be remotely accessed by the home RAS 150 and theremote RAS 130 and may support an out-of-band protocol by which the RATAprofile can be transmitted to the remote RAS 130.

If the remote RAS 130 is in a network address translation (NAT) basedprivate network, the remote RAS 130 provides a NAT traversing address tothe home RAS 150 via a session initiation protocol (SIP) server 113 inorder to be accessed by the home RAS 150. To this end, in the remote RAS130, an address of the SIP server 113 to which the NAT traversingaddress of the remote RAS 130 has been subscribed, is subscribed to by amanagement console of a network to which the remote RAS 130 belongs. Inaddition, if the remote RAS 130 receives a NAT traversing service from atraversal using relays around NAT (TURN) server, an address of a TURNserver corresponding to the NAT traversing service is subscribed to by amanagement console of a network to which the remote RAS 130 belongs.

A transport address (TA) set is a set of addresses, each of which can bea candidate for an address to traverse the NAT. The addresses in the TAset are pairs of <IP address>:<Port Number>. Three types of TA,including a TA, a reflexive TA, and a relaying TA, may be used. A TA setis a group of independent TAs.

A TA includes a pair of an IP address allocated to a UPnP device and aport number of a service to access. A reflexive TA includes, when theremote RAS 130 is in a NAT-based private network, a pair of a public IPaddress allocated to the network and a port number allocated to either aterminal or a service to access. A reflexive TA may be obtained from aresponse to an inquiry to a simple traversal of User Datagram Protocol(UDP) through NATs (STUN) server. A relaying TA includes, when theremote RAS 130 is in a NAT-based private network and packets destinedfor the private network are relayed by the TURN server, a pair of apublic IP address allocated to the TURN server and a port number of aservice to access. Since a method of forming a TA set in each device isdefined in standard specification of the STUN and the TURN, furtherdescriptions thereof will be omitted for conciseness.

The home RAS 150 transmits a SIP invite message to the SIP server 113and receives a SIP response message from the SIP server 113 in responseto the SIP invite message, so as to obtain the NAT traversing address ofthe remote RAS 130. The SIP response message includes the NAT traversingaddress of the remote RAS 130.

Meanwhile, when the home RAS 150 is also in a NAT-based private network,the home RAS 150 loads its NAT traversing address into the SIP invitemessage to transmit the NAT traversing address to the SIP server 113.Further descriptions thereof will be provided with reference to FIGS. 7through 9.

A method of generating and transmitting a RATA profile in order to beremotely accessed by the home RAS 150 and the RAC 170 to provide ahome-to-remote access client (RAC) remote access service between thehome RAS 150 and a RAC 170 by using the management console 190, and amethod of traversing NAT to provide a remote access service when the RAC170 is in a NAT-based private network may be identical to a method ofproviding the home-to-home remote access service between the home RAS150 and the remote RAS 130. Thus, further descriptions of a method ofproviding home-to-RAC remote access service will be omitted forconciseness.

A home network and a remote network are home-to-home remotely accessedand unified as one network via a virtual private network (VPN) tunneland thus, a UPnP service may be provided via the unified network. Inthis case, in the remote RAS 130 in the remote network and the RAC 170,the RATA profile may be dynamically set up by the management console 190in order to be home-to-home and home-to-RAC remotely accessed.

In addition, a plurality of UPnP devices, provided by the RAC 170 andthe remote RAS 130, may remotely access each other. Thus, various userscenarios that are three-box model based and are constituted between thehome network provided by the home RAS 150, a first remote networkprovided by the RAC 170 and a second remote network provided by theremote RAS 130 may be supported.

Also, even if the home RAS 150, the RAC 170 or the remote RAS 130 are ina NAT-based private network, the NAT traversing address is provided toeach other by using a SIP so that the remote access service traversingthe NAT may be provided.

FIG. 2 shows an exemplary architecture providing a home-to-home remoteaccess service between a remote RAS 230 and a home RAS 250 by using amanagement console 290 within a moving RAC 270 that remotely accesses tothe home RAS 250.

Referring to FIG. 2, when the management console 290 exists within themoving RAC 270 that remotely accesses to the home RAS 250, themanagement console 290 provides parameters, which are required forsetting an RATC between the remote RAS 230 and the home RAS 250, in theform of a RATA profile.

The management console 290 may discover the home RAS 250 through remoteaccess and then may transmit the RATA profile to the home RAS 250 byusing UPnP remote access (RA) actions. Also, the management console 290may discover the remote RAS 230 by using UPnP device architecture (DA)and transmit the RATA profile to the remote RAS 230 by using UPnP RAactions. Further descriptions thereof will be provided with reference toFIG. 6.

A home network and a remote network are home-to-home remotely accessedand unified as one network via a VPN tunnel and thus, a UPnP service maybe provided in the unified network. In this case, in the remote RAS 230in the remote network, a RATA profile may be dynamically set up by themanagement console 290 within the moving RAC 270 that remotely accessesto the home RAS 250 in order to be home-to-home remotely accessed. Anadditional out-of-band protocol may not be required to transmit the RATAprofile to the remote RAS 230.

FIG. 3 is a diagram showing an exemplary process of transmitting a RATAprofile in order to provide a home-to-home remote access service.

In operation 311, an identifier (ID) of the remote RAS 350 is input to ahome RAS 330 by using a management console 310. It is assumed that theidentifier of the remote RAS 350 is known to be secure by using anadditional method, for example, through a telephone call. The ID of theremote RAS 350 may be a product identification number (PIN) which is anidentifier allocated to the remote RAS 350 when the remote RAS ismanufactured, or another identifier allocated in another manner may beused.

In operation 370, the home RAS 330 sets a temporary secure authenticatedchannel (SAC) 370 with the remote RAS 350 by using the ID of the remoteRAS 350 and SIP ID information. The SAC may be set by using a transportlayer security (TLS) protocol that is implemented by using a pre-sharedkey. In other implementations, the SAC is set by using another method.The TLS protocol is defined in RFC 4346 and thus, further descriptionsthereof will be omitted for conciseness.

The management console 310 receives information, used for setting a VPN,from the remote RAS 350 via the temporary SAC 370 and transmits agenerated credential and a RATA profile to the remote RAS 350 via thetemporary SAC 370. In this case, information may be transmitted to orreceived from the SAC 370 by using an out-of-band protocol such ashypertext transfer protocol (HTTP) and secure-hypertext transferprotocol (S-HTTP). In other implementations, a protocol other than anout-of-band protocol may be used.

Meanwhile, the management console 310 discovers the home RAS 330 andthen receives information, used for setting a VPN, from the home RAS 330via a UPnP RA action and transmits the generated credential and the RATAprofile to the home RAS 330 via the UPnP RA action.

In operations 312 and 313, the management console 310 transmits amessage regarding an inquiry to RATA capability information about eachof the home RAS 330 and the remote RAS 350, to the home RAS 330 and theremote RAS 350, respectively, and receives the RATA capabilityinformation from each of the home RAS 330 and the remote RAS 350.

In operation 314, the management console 310 generates a credentialbased on the RATA capability information, supported by the home RAS 330and the remote RAS 350.

In operations 315 and 316, the management console 310 transmits thecredential to each of the home RAS 330 and the remote RAS 350.

In operation 317, the management console 310 generates a RATA profile tobe remotely accessed, based on the credential.

In operations 318 and 319, the management console 310 transmits the RATAprofile to each of the home RAS 330 and the remote RAS 350.

FIG. 4 is a diagram showing an exemplary process of updating a RATAprofile in order to provide a home-to-home remote access service.

In RA Architecture 1.0, RATA Config Service information is not providedto the home RAS 430 via a VPN. Rather, the RATA Config Serviceinformation is provided to the home RAS 430 via a remote accessdiscovery agent (RADA) Sync service so as to provide the home-to-homeremote access service so that a management console 410 of the home RAS430 can update or delete an existing RATA profile by using a UPnPaction. In this case, the information of RATA Config Service may belimited to be provided only if necessary, by using filtering using awhite list or a black list.

In operations 411 and 412, the management console 410 transmits amessage regarding an inquiry about RATA capability information abouteach of the home RAS 430 and the remote RAS 450 to the home RAS 430 andthe remote RAS 450, respectively, and receives the RATA capabilityinformation from the home RAS 430 and the remote RAS 450.

In operation 413, the management console 410 updates the credentialbased on the RATA capability information that are supported by the homeRAS 430 and the remote RAS 450.

In operations 414 and 415, the management console 410 transmits theupdated credential to each of the home RAS 430 and the remote RAS 450.

In operation 416, the management console 410 updates a RATA profile tobe remotely accessed, based on the updated credential.

In operations 417 and 418, the management console 410 transmits theupdated RATA profile to each of the home RAS 430 and the remote RAS 450.

FIG. 5 is a diagram showing an exemplary process of deleting a RATAprofile in order to provide a home-to-home remote access service.

In operations 511 and 512, a management console 510 transmits a messageregarding an inquiry to a RATA profile about each of the home RAS 530and the remote RAS 550 to the home RAS 530 and the remote RAS 550,respectively, and receives the RATA profile from the home RAS 530 andthe remote RAS 550, respectively.

In operations 513 and 514, the management console 510 transmits amessage for deleting the RATA profile about each of the home RAS 530 andthe remote RAS 550 to the home RAS 530 and the remote RAS 550,respectively.

FIG. 6 is a diagram showing an exemplary process of transmitting a RATAprofile by using a management console 610 within a moving RAC (notshown) that remotely accesses to a home RAS 630, in order to provide ahome-to-home remote access service.

When the management console 610 exists within the removing RAC (notshown) that remotely accesses to the home RAS 630, the managementconsole 610 provides parameters, which are required for setting an RATCbetween the home RAS 630 and a remote RAS 650, in the form of a RATAprofile.

The management console 610 discovers the home RAS 630 through remoteaccess and then transmits the RATA profile to the home RAS 630 via aUPnP RA action (operation 681). In addition, since the managementconsole 610 and the remote RAS 650 exist in the same network, themanagement console 610 discovers the remote RAS 650 via UPnP DA andtransmits the RATA profile to the remote RAS 650 via the UPnP RA action(operation 682). Thus, an additional out-of-band protocol may not berequired to transmit the RATA profile to the remote RAS 650.

In operations 612 and 613, the management console 610 transmits amessage regarding an inquiry about RATA capability information abouteach of the home RAS 630 and the remote RAS 650 to the home RAS 630 andthe remote RAS 650, respectively, and receives the RATA capabilityinformation from each of the home RAS 630 and the remote RAS 650.

In operation 614, the management console 610 generates a credentialbased on the RATA capability information that is supported by the homeRAS 630 and the remote RAS 650.

In operations 615 and 616, the management console 610 transmits thecredential to each of the home RAS 630 and the remote RAS 650.

In operation 617, the management console 610 generates a RATA profile tobe remotely accessed, based on the credential.

In operations 618 and 619, the management console 610 transmits the RATAprofile to each of the home RAS 630 and the remote RAS 650.

FIG. 7 is a diagram showing an exemplary process of traversing NAT byusing a SIP.

When a remote RAS 720 is in a NAT-based private network, the remote RAS720 provides a NAT traversing address to a home RAS 770 in order to beaccessed by the home RAS 770.

To this end, in operation 782, in the remote RAS 720, an address of asession initiation protocol (SIP) server 750 to which the NAT traversingaddress of the remote RAS 720 for a temporary SAC and a VPN channel(operation 786) has been subscribed, is subscribed to by a managementconsole 710 of a network to which the remote RAS 720 belongs.

As described above, the NAT traversing address of the remote RAS 720 isa TA set, and a reflexive TA from among a TA, the reflexive TA, and arelaying TA may be obtained from a response to an inquiry to a STUNserver (operation 781).

In operation 783, the remote RAS 720 subscribes its NAT traversingaddress in the SIP server 750 to the temporary SAC and the VPN channel(operation 786).

In operation 787, the home RAS 770 receives a SIP ID of the remote RAS720 from a management console 790.

In operation 784, the home RAS 770 transmits a SIP invite message to theSIP server 750 so as to obtain the NAT traversing address of the remoteRAS 720 corresponding to the SIP ID of the remote RAS 720.

In operation 785, the home RAS 770 receives a SIP response message fromthe SIP server 750 in response to the SIP invite message. The SIPresponse message includes the NAT traversing address of the remote RAS720.

Meanwhile, when the home RAS 770 is in a NAT-based private network, thehome RAS 770 loads its NAT traversing address into the SIP invitemessage to transmit the NAT traversing address to the SIP server 750.

FIG. 8 is a diagram showing an exemplary process of traversing NAT,provided by a TURN server 850, by using a SIP.

In operation 881, when a NAT traversing service is provided by the TURNserver 850 to a remote RAS 820, in the remote RAS 820, an address of theTURN server 850 corresponding to the NAT traversing service issubscribed to a management console 810 of a network to which the remoteRAS 820 belongs.

In operation 882, a relaying TA among a TA set corresponding to the NATtraversing address is allocated to the remote RAS 820 by using a TURNprotocol. A relaying TA includes, when the remote RAS 820 is in aNAT-based private network and packets destined for the private networkare relayed by the TURN server 850, a pair of a public IP addressallocated to the TURN server 850 and a port number of a service toaccess.

In operation 883, in the remote RAS 820, an address of a SIP server 860to which the NAT traversing address of the remote RAS 820 for atemporary SAC and a VPN channel (operation 887) has been subscribed, issubscribed to by a management console 810 of a network to which theremote RAS 820 belongs.

In operation 884, the remote RAS 820 subscribes its NAT traversingaddress to the temporary SAC and the VPN channel (operation 887) in theSIP server 860.

In operation 888, the home RAS 870 receives a SIP ID of the remote RAS820 from a management console 890.

In operation 885, the home RAS 870 transmits a SIP invite message to theSIP server 860 so as to obtain the NAT traversing address of the remoteRAS 820 corresponding to the SIP ID of the remote RAS 820.

In operation 886, the home RAS 870 receives a SIP response message fromthe SIP server 860 in response to the SIP invite message. The SIPresponse message includes the NAT traversing address of the remote RAS820.

FIG. 9 is a diagram showing an exemplary process of transmitting addressinformation for setting a SAC and a VPN, which traverse NAT, by using aSIP and a format for describing a set of NAT traversing addresses usinga session description protocol (SDP).

In operation 910, a home RAS 991 describes information about a TA setcorresponding to its NAT traversing address by using a SDP and transmitsthe information in the form of a SIP invite message. Referring to FIG.9, fields of the information about a TA set corresponding to the NATtraversing address are encoded in the SDP format.

In operation 920, the home RAS 991 receives the information about the TAset corresponding to the NAT traversing address with respect to a remoteRAS (not shown) from a SIP server 992. Referring to FIG. 9, fields ofthe information about the TA set corresponding to the NAT traversingaddress are encoded in the SDP format.

Meanwhile, although not shown, the information about the TA setcorresponding to the NAT traversing address may become payloads of a SIPpacket in an extensible markup language (XML) format and may betransmitted to or received from the SIP server 992.

FIG. 10 shows the structure of an exemplary management console 1000.Referring to FIG. 10, the management console 1000 includes a RATAconfiguration information obtaining unit 1010, an identifier (ID)transmitting unit 1012, a SIP server subscribing unit 1014, a TURNserver subscribing unit 1016, a RATA profile deleting unit 1020, a RATAprofile inquiring unit 1022, a RATA capability information receivingunit 1024, a RATA profile generating unit 1026, a RATA profiletransmitting unit 1028, and a RATA profile updating unit 1032.

The ID transmitting unit 1012 transmits an ID of a remote RAS 1060 to ahome RAS 1050, wherein the ID of the remote RAS 1060 is used for settinga SAC destined for the remote RAS 1060 by using the home RAS 1050. Also,the ID transmitting unit 1012, when the remote RAS 1060 is in aNAT-based private network, transmits a SIP ID of the remote RAS 1060 tothe home RAS 1050 so that a NAT traversing address by which the home RAS1050 accesses to the remote RAS 1060, may be obtained.

The RATA capability information receiving unit 1024 transmits a messageregarding an inquiry about RATA capability information of the home RAS1050 and the remote RAS 1060 to the home RAS 1050 and the remote RAS1060, respectively, and receives RATA capability information from eachof the home RAS 1050 and the remote RAS 1060.

The RATA profile generating unit 1026 generates a credential based onthe RATA capability information that are supported by the home RAS 1050and the remote RAS 1060 and generates a RATA profile of each of the homeRAS 1050 and the remote RAS 1060 based on the credential.

The RATA profile transmitting unit 1028 transmits the RATA profile,which is generated for remote access, to the home RAS 1050 and theremote RAS 1060, respectively.

The RATA configuration information obtaining unit 1010 obtains RATAconfiguration information including a credential and a RATA profile ofthe remote RAS 1060 from the home RAS 1050. For example, in RAArchitecture 1.0, RATA Config Service information is not provided via aVPN. The RATA Config Service information may be provided to the home RAS1050 via a RADA Sync service so that a management console of anothernetwork can update or delete an existing RATA profile.

The RATA profile updating unit 1032 updates a RATA profile to beremotely accessed based on the RATA capability information of the homeRAS 1050 and the remote RAS 1060, which are received by the RATAcapability information receiving unit 1124.

The RATA profile inquiring unit 1022 transmits a message regarding aninquiry to a RATA profile of each of the home RAS 1050 and the remoteRAS 1060 to the home RAS 1050 and the remote RAS 1060, respectively.

The RATA profile deleting unit 1020 transmits a message for deleting theinquired RATA profile to the home RAS 1050 and the remote RAS 1060,respectively.

The SIP server subscribing unit 1014, when the management console 1000is in a NAT-based private network, transmits an address of a SIP serverto which a RAS of the private network subscribes a public address totraverse NAT, to the RAS of the private network.

The TURN server subscribing unit 1016, when the management console 1000is in a NAT-based private network and a relaying service to traverse NATis provided to the private network via a TURN server, transmits anaddress of the TURN server, which is subscribed to by a RAS of theprivate network, to the RAS of the private network.

The RATA capability information receiving unit 1024 and the RATA profileinquiring unit 1022 receive the RATA capability information and the RATAprofile from the home RAS 1050 by using a UPnP action, and the IDtransmitting unit 1012, the RATA profile transmitting unit 1028, and theRATA profile deleting unit 1020 transmit an ID and a SIP ID of theremote RAS 1060, the RATA profile, and the message for deleting the RATAprofile to the home RAS 1050 by using the UPnP action.

The RATA capability information receiving unit 1024 and the RATA profileinquiring unit 1022 receive the RATA capability information and the RATAprofile from the remote RAS 1060 on a SAC by using an out-of-bandprotocol, and the RATA profile transmitting unit 1028 and the RATAprofile deleting unit 1020 transmit the RATA profile and the message fordeleting the RATA profile to the remote RAS 1060 on the SAC by using theout-of-band protocol. The out-of-band protocol includes HTTP and S-HTTP.

When the management console 1000 moves to a remote network, the RATAcapability information receiving unit 1024 and the RATA profileinquiring unit 1022 receive the RATA capability information and the RATAprofile from the home RAS 1050 by using the UPnP action through remoteaccess, and the ID transmitting unit 1012, the RATA profile transmittingunit 1028, and the RATA profile deleting unit 1020 transmit the SIP IDof the remote RAS 1060, the RATA profile, and the message for deletingthe RATA profile to the home RAS 1050 by using the UPnP action throughremote access.

Also, when the management console 1000 moves to the remote network, theRATA capability information receiving unit 1024 and the RATA profileinquiring unit 1022 discover the remote RAS 1060 and then receive theRATA capability information and the RATA profile from the remote RAS1060 by using the UPnP action, and the RATA profile transmitting unit1028 and the RATA profile deleting unit 1020 discover the remote RAS1060 and then transmit the RATA profile and the message for deleting theRATA profile to the remote RAS 1060 by using the UPnP action.

Thus, when the management console 1000 moves to the remote network, anadditional out-of-band protocol may not be required for transmitting theRATA profile to the remote RAS 1060 by using the management console1000.

FIG. 11 shows the structure of an exemplary home RAS 1100. Referring toFIG. 11, the home RAS 1100 includes a TA managing unit 1110, a SIPpayload generating unit 1112, a SIP packet transmitting unit 1114, a TAsetting unit 1120, a SIP payload extracting unit 1122, a SIP packetreceiving unit 1124, and an ID receiving unit 1130.

The ID receiving unit 1130 receives an ID of a remote RAS from amanagement console 1160, where the ID of the remote RAS is used forsetting a SAC destined for the remote RAS by using the home RAS 1100.Also, the ID receiving unit 1130, when the remote RAS is in a NAT-basedprivate network, receives a SIP ID of the remote RAS from the managementconsole 1160 so that a NAT traversing address by which the home RAS isaccessed by the remote RAS, can be obtained.

The TA managing unit 1110, when the home RAS 1100 is in a NAT-basedprivate network, generates TA set information corresponding to candidateIP addresses to access the home RAS 1100.

The SIP payload generating unit 1112 generates a payload of a SIP packetincluding the TA set information corresponding to the candidate IPaddresses to access the home RAS 1100. The payload of the SIP packet maybe in the form of XML or SDP. In other implementations, the payload ofthe SIP packet is in a form other than XML or SDP.

The SIP packet transmitting unit 1114 transmits the SIP packet to theSIP server 1150. The SIP packet receiving unit 1124 receives the SIPpacket including the TA set information corresponding to the candidateIP addresses to access the remote RAS as the payload of the SIP packet,from the SIP server. The SIP payload extracting unit 1122 extracts thepayload including the TA set information of the remote RAS from the SIPpacket. The TA setting unit 1120 sets the TA set information of theremote RAS within the home RAS 1100.

According to example(s) described above, there is provided a method andapparatus for providing a remote access service to a universal plug andplay (UPnP) remote access server (RAS) and a UPnP remote access client(RAC) in a remote network by setting channel setting information (aremote access transport agent (RATA) profile) for remote access andtraversing network address translation (NAT).

The methods described above may be recorded, stored, or fixed in one ormore computer-readable media that includes program instructions to beimplemented by a computer to cause a processor to execute or perform theprogram instructions. The media may also include, alone or incombination with the program instructions, data files, data structures,and the like. Examples of computer-readable media include magneticmedia, such as hard disks, floppy disks, and magnetic tape; opticalmedia such as CD ROM disks and DVDs; magneto-optical media, such asoptical disks; and hardware devices that are specially configured tostore and perform program instructions, such as read-only memory (ROM),random access memory (RAM), flash memory, and the like. Examples ofprogram instructions include machine code, such as produced by acompiler, and files containing higher level code that may be executed bythe computer using an interpreter. The described hardware devices may beconfigured to act as one or more software modules in order to performthe operations and methods described above, or vice versa.

A number of exemplary embodiments have been described above.Nevertheless, it will be understood that various modifications may bemade. For example, suitable results may be achieved if the describedtechniques are performed in a different order and/or if components in adescribed system, architecture, device, or circuit are combined in adifferent manner and/or replaced or supplemented by other components ortheir equivalents. Accordingly, other implementations are within thescope of the following claims.

What is claimed is:
 1. A method of providing a remote access service byusing a home remote access server (RAS), the method comprising:receiving a session initiation protocol (SIP) identifier (ID) of aremote RAS from a management console; generating a payload of a SIPpacket comprising a SIP ID of the remote RAS and transport address (TA)set information corresponding to candidate Internet protocols (IP)addresses to access the home RAS; and transmitting the SIP packet to aSIP server.
 2. The method of claim 1, further comprising: receiving theSIP packet comprising the TA set information corresponding to thecandidate IP addresses to access the remote RAS corresponding to the SIPID of the remote RAS as a payload of the SIP packet, from the SIPserver; extracting a payload comprising TA set information of the remoteRAS from the SIP packet; and setting TA set information of the remoteRAS.
 3. The method of claim 1, wherein the TA set information of thehome RAS comprises a TA, a reflexive TA, and a relaying TA, the TAcomprises a pair of an IP address allocated to the home RAS and a portnumber of a service to access, the reflexive TA comprises, when the homeRAS is in a network address translation (NAT)-based private network, apair of a public IP address allocated to the private network and a portnumber of a service to access, and the relaying TA comprises, when thehome RAS is in a NAT-based private network and packets destined for theprivate network are relayed by a traversal using relays around NAT(TURN) server, a pair of a public IP address allocated to the TURNserver and a port number of a service to access.
 4. The method of claim2, wherein the TA set information of the remote RAS comprises a TA, areflexive TA, and a relaying TA, the TA comprises a pair of an IPaddress allocated to the remote RAS and a port number of a service toaccess, the reflexive TA comprises, when the remote RAS is in aNAT-based private network, a pair of a public IP address allocated tothe private network and a port number of a service to access, and therelaying TA comprises, when the remote RAS is in a NAT-based privatenetwork and packets destined for the private network are relayed by aTURN server, a pair of a public IP address allocated to the TURN serverand a port number of a service to access.
 5. The method of claim 1,further comprising generating TA set information corresponding to thecandidate IP addresses to access the home RAS.
 6. The method of claim 1,wherein the payload of the SIP packet is in a form of extensible markuplanguage (XML) or session description protocol (SDP).
 7. The method ofclaim 1, wherein the remote RAS comprises a remote remote access client(RAC) or a remote RAS.
 8. A home remote access server (RAS), comprising:an identifier (ID) receiving unit configured to receive a sessioninitiation protocol (SIP) ID of a remote RAS from a management console;a SIP payload generating unit configured to generate a payload of a SIPpacket comprising a SIP ID of the remote RAS and transport address (TA)set information corresponding to candidate Internet protocols (IP)addresses to access the home RAS; and a SIP packet transmitting unitconfigured to transmit the SIP packet to a SIP server.
 9. The home RASof claim 8, further comprising: a SIP packet receiving unit configuredto receive the SIP packet comprising the TA set informationcorresponding to the candidate IP addresses to access the remote RAScorresponding to the SIP ID of the remote RAS as a payload of the SIPpacket, from the SIP server; a SIP payload extracting unit configured toextract a payload comprising TA set information of the remote RAS fromthe SIP packet; and a TA setting unit configured to set TA setinformation of the remote RAS.
 10. The home RAS of claim 8, wherein theTA set information of the home RAS comprises a TA, a reflexive TA, and arelaying TA, and the TA comprises a pair of an IP address allocated tothe home RAS and a port number of a service to access, the reflexive TAcomprises, when the home RAS is in a network address translation(NAT)-based private network, a pair of a public IP address allocated tothe private network and a port number of a service to access, and therelaying TA comprises, when the home RAS is in a NAT-based privatenetwork and packets destined for the private network are relayed by atraversal using relays around NAT (TURN) server, a pair of a public IPaddress allocated to the TURN server and a port number of a service toaccess.
 11. The home RAS of claim 9, wherein the TA set information ofthe remote RAS comprises a TA, a reflexive TA, and a relaying TA, andthe TA comprises a pair of an IP address allocated to the remote RAS anda port number of a service to access, the reflexive TA comprises, whenthe remote RAS is in a NAT-based private network, a pair of a public IPaddress allocated to the private network and a port number of a serviceto access, and the relaying TA comprises, when the remote in a NAT-basedprivate network and packets destined for the private network are relayedby a TURN server, a pair of a public IP address allocated to the TURNserver and a port number of a service to access.
 12. The home RAS ofclaim 8, further comprising a TA managing unit configured to generate TAset information corresponding to the candidate IP addresses to accessthe home RAS.
 13. The home RAS of claim 8, wherein the payload of theSIP packet is in a form of extensible markup language (XML) or sessiondescription protocol (SDP).
 14. The home RAS of claim 8, wherein theremote RAS comprises a remote remote access client (RAC) or a remoteRAS.
 15. A computer-readable storage medium storing a program to providea remote access service by using a home remote access server (RAS),comprising instructions to cause a computer to: receive a sessioninitiation protocol (SIP) identifier (ID) of a remote RAS from amanagement console; generate a payload of a SIP packet comprising a SIPID of the remote RAS and transport address (TA) set informationcorresponding to candidate Internet protocols (IP) addresses to accessthe home RAS; and transmit the SIP packet to a SIP server.